Bias transmitter



Dec. 19,1939. E. w. F. HANKE Er A1. 2,133,613

BIAS TRANSMITTER Filed Sept. 3, 1937 `4 SheeLS-Sheel l EDWIN WILLIAM F. HANKE WALTER J.ZENNER Pfff Dec. 19, 1939. E. w. F. HANKE Er AL BIAS TRANSMITTER Filed Sept. I5, 1937 4 Sheets-Sheet 2 Flc. 3

INVENTORS EDWIN WILLIAM F. HANKE Flc. 4`

BY WALTER J. ZENNER Jiffy ATTORNEY. 4'

Dec. 1-9, 1939.' E. w. F. HANKE ET AI.

BIAS TRANSMITTER Filed Sept. 3, 1937 4 sheets-sheet 3 @MII IGI

|69 |62 NE I INI/ENTORS EDwIN WILLIAM F HANKE BY WALTER .I ZENNER z' I ORNEY.'

Dec. 19, 1939. E. w. F. HANKE E-r AI. 2,183,613 l BIAS TRANSMITTER Filed Sept. 3, 1937 4 Sheets-Sheet FIG. 6 I INE |78] FIG. 7 LINE I7 w DISPLACEABLE INVENTOR. EDWIN WILLIAM F.y HANKE BY WALTER J. ZENNER Patented Dec. 19, 1939 UNITED STATES PATENT OFFICE BIAS TRANSMITTER of Delaware l Application September 3, 1937, Serial No. 162,328

16 Claims.

The present invention relates to telegraph systems and apparatus therefor and more particularly to testing apparatus for ascertaining the marginal operating characteristics or tolerance of printing telegraph mechanism.

Due to certain uncontrollable phenomena occuring in connection with the transmission of telegraph signals, conditions prevail which detrimentally affect' signal transmission and which,

due in part to inductive and capacitative inuences, produce certain distortions in telegraph signals. In an endeavor to immunize telegraph receiving equipment to the usual ranges of signal distortion, terminal equipment is designed to accommodate certain degrees of signal distortion and/or bias. rizhis margin or capacity to respond satisfactorily to certain degrees of signal distortion may be termed tolerance.

in testing terminal equipment to determine its tolerance, synthetically distorted signals are reproduced and transmitted having a known degree and direction of distortion, and the effect ci said signals' upon the terminal apparatus is observed until a point is reached at which an erroneous response is produced. Particularly in the case of telegraph printers, tolerance standards are customarily established as a condition prerequisite to passing inspection tests and equipment to acceptable for commercial operation and service must be capable of receiving and responding correctly to signals having predetermined ranges of distortion.

Acc ingly, it has been found expedient to e apparatus icr transmitting accurately measurable distorted signals in which each factor of distortion may be independently calculated and determined and thus make possible the attainment of a basis `for calihrating the tolerance 'f "ng of the receiving equipment.

40 present in" is related in function to the structure described in United States Patent No, 2,936,953?? issued to W. Y. Lang by reason of its provision or a rotatable annular index which carries a standard start-stop code pattern rotatable into position for the purpose of comparison with signals under test, the protures will become more apparent during the course of the following description.

The margin of distortion hy which test signals of any' type differ from theoretically perfect signals is here classified into two major divisions 5 each having two subordinate varieties. For convenience, the two major types of distortion are referred to as (l) bias and (2) end distortion. Each oi these types may be applied to marking or spacing signais so that bias may be considered as comprised einer of marking bias or spacing bias while similarly end distortion is classiable as marking end distortion or spacing end distortion.

Apparatus of the design herewith contemplated nds many uses and applications in the testing of telegraph signaling equipment. A typical use for which it is appropriate is in testing telegraph printers for signal tolerance. Bias and end distortion signals of both marking and spacing types are transmitted to a printer, the degree of distortion being increased until the failing point is obtained. in each instance a stroboscopic device may be cut in after the failing point is attained and in so doing, there will be produced a visual portrayal of the signal. From this the technician or adjuster may be apprised of special apparatus characteristics not otherwise discernible. The information thus obtained not only indicates the existent tolerance, but also any adjustment which may equalize or distribute more evenly any avaiialole surplus when such surplus is preponderous.

The present invention is directed to apparatus consisting of a Atransmitting distributor having means for introducing calibrated variations of any of the aforementioned classes of end distortion and bias and of deter ining accurately the degree of distortion or variation of each signal *from a known standard. In addition, the apparatus embraces a unique type of visible indeX comprising a rotatable neon lamp and an annularly rotatable scale capable of being adjusted to afford a reading throughout 350. This index is utilized not only for measuring the signal distortion oi the transmitted test signals but it may also be used for determining the distortion or any other visible characteristics of incoming line signals received from a remotely located transmitter. When employed in the latter manner, the unit does not perform as a transmitter but instead as a receiver having a 4 visual index for inspecting the characteristics of incoming line signals.

Accordingly, the main object of the present invention is the provision of testing equipment for printing telegraph apparatus, which is comparatively simple and highly efficient, and which is capable of producing signals of varying types and degrees of distortion to simulate signal characteristics which might be expected under various operating conditions.

Another object of the present invention is the provision of a transmitter for producing eccentric permutation coole signals, and means for determining accurately various classes and degrees of distortion.

Another object of the present invention is to provide a rotatable neon tube carrier whose speed of rotation may be synchronized in accordance wit'h known standard forms of transmission, and in which an annular index comprising a rotatable inscribed scale may be employed for observ' `ing Variations in the visual pattern characteristics of transmitted signals.

In addition to the aforegoing objects, other fea tures which have been developed include a transmitting mechanism having a synchronizing starter, which comprises a manually controllable device released at any time but effective to cut in and out of the transmission line the transmitting apparatus only during the occurrence of the stop impulse interval regardless of the particular instant at which the manual operation is initiated.

In its preferred embodiment, the present device comprises a unitary structure having a large disc dial constituting an index from which the aforedescribed variations in signal characteristics may be observed. At each side of the index dial is located a tier of control devices or switches. As will be described, these switches control the transmitter so that it may be adapted to several conditions of signal distortion.

The neon tube is carried upon the rotating arm and as marking signals are received and impressed upon the electrode of the tube, luminous patterns are produced upon a dark background. Since the transmitting shaft is rotating in accordance with standard start-stop frequency, these patterns may be made to recur in the same relative position for corresponding signal intervals of consecutive signals. If any variation in speed is noticeable, means are provided in accordance with the present embodiments for introducing correction. A ring is mounted so that its annular inner surface lies just outside the path described by the rotating neon lamp. Engraved markings on the ring are arranged so as to coincide with a standard start-stop signal. By adjusting the relative position of the ring to the visual image of the incoming signal, the degree and precise nature of distortion of incoming signals may be ascertained by noting the diiference or differences between the incoming signal and the standard which is symbolized by the markings on the ring.

In the present embodiment an arbitrary standard test message is formed upon the peripheral surface of a set of discs. Thismessage may be employed for ordinary testing, but as an alternative method there is also provided a means for rendering the standard test message mechanismv ineffective for transmission and for substituting therefor a transmitting arrangement for sending solely either the letter R or the letter Y, two

Acharacters especially adapted to test signaling.

`iicationVv following hereinafter wherein corresponding parts have been indicated by similar reference characters, and wherein:

Fig. 1 is a, front elevation of the present invention having a portion of the transmitter broken away to reveal the distributor arm and phasing arrangement;

Fig. 2 is a view taken similar to Fig. l but wherein additional fragments of the mechanism have been broken away to reveal the test message apparatus, contact, and a portion of the driving train;

Fig. 3 is a transverse sectional View taken approximately on line 3-73 of Fig. 2;

Fig. 4 is a vertical sectional View with the lower portion of the apparatus shown in side elevation and is taken approximately on line li-li of Fig. 2;

Fig. 5 is a circuit drawing illustrating the electrical connections of the apparatus featured in Figs. 1 to 4;

Figs. 6 to 9 inclusive are diagrammatic detail views illustrating in a simplified manner the multiple circuit arrangements which may be obtained by the use of the toggle control switches illustrated in Figs. 1 and 2 and featuring particularly the relative positions of the segmented distributor rings;

Figs. 6a to 9d, inclusive, are curve charts each located beneath an associated figure described in the preceding paragraph and illustrating diagrammatically the signal formations associated therewith; and

Fig. 10 is a detailed perspective view of the switching mechanism for shifting the control of transmission between the set of coded discs associated with the test message and the apparatus employed for straight R and Y signal transmisslon.

In the accompanying drawings, the reference character l l denotes a base casting with the fore portion of which there is integrally formed a flanged face l2, Fig. 4. The contour of face i2 is designed to conform with that of a circular dial indicated generally by the reference character I3 and escutcheon plates Ml and i5. Plate I4 is located at the left of the dial i3, as viewed in Fig. 1, and through it there extend toggle switch handles i6, lll, i8, and 19 as well as motor switch 2 l Plate l5, which is symmetrical to and opposite plate i4, forms a background to three rotatable knobs 22, 23, and 24.

A main distributor shaft 25, concentric of dial I3, is frictionally driven by an electric motor 26, whose driving worm 21 meshes with a worm wheel 28 frictionally supported between slip washers 2Q of a friction clutch 3i, Figs. 3 and 4. Distributor shaft 25 carries forward the rotation through a tributary train which includes a driving gear 32, a driven wheel 33, and a stub shaft 34, best indicated in Fig. 2. A worm 35, connected to the lower end of stub shaft'll, imparts re duced speed rotation to an assembly on shaft 35 consisting of a driven gear 3'! and a plurality of coded discs 38.

As indicated best in Fig. 3, the foremost portion of shaft 25 is journaled in a bearing 39 and protrudes through the plane occupied by segment supporting discs M and ft2. To the protruding section is secured a triangular plate 43, Fig. 2, one of whose extremities carries a supporting bracket 44. The latter has integraliy associated with it a mask i5 and a receptacle i6 into which is fitted a neon tube 4l. Mask l5 is slotted as at i8 and through this slot is visible a linear light beam during the time that the neon tube 4'! is lighted. Since the assembly is rotatable together With shaft 25, intervals during which the light beam is visible cause to appear arcuate glow images in a circular path and because isochronous telegraph signals are passed through the neon tube iilament coincident with the cyclic rotation of shaft 25, signal impulse intervals of repeated character signals having deiinite positions in cycle may be made to occur during successive cycles in substantially the same relative position. When a character signal is repeated for a denite period, the repeated occurrences of arc glow images may be observed as a relatively constant condition and may be compared with a standard 49 for determining the constancy of its characteristics. The standard 49 is so called because its -radial markings are so spaced from each other as to be accurately representative of an ideal signal, that is to say, of a signal which is entirely free of any distortion factor.

-Circular standard or index 49 is constructed of an annular ring 5l having a groove 52 internally thereof within which are fitted component segments 53, Fig. 2, secured to the iront face l2. A fascia 5t, fastened to the annular ring 5l by means of screws 55, has inscribed on its exposed surface, spaced radial gradations 5t, which are predeterminedly plotted to agree, in major angular markings, with the divisions of a theoretically perfect code signal.

Current is supplied to the neon tube 4'! over a pair of conductors 5l, Fig. 5, which connect the terminals of said tube with distributor brushes 58 that wipe across continuous rings Concentric with the rings 59-5G and also with the distributor shaft 25 are a pair of continuous rings @i and @2 and a pair of segmented rings indicated generally 63 and 64. All of the concentric rings, except ring 64, are set into the supporting disc as best indicated in Figs. 3, 4, and 5, while segmented ring 64 alone is set into the face of the outer supporting disc 4|. However, all of the rings 5S to 6G are disposed in a single plane and they-are conveniently traversed by the brushes of a single distributor' arm 55.

Rings t! to lid are traversed by brushes 6B, 57, ti?, and respectively, With brush 61 electrically connected to the brush 68 andbrush St electrically connected to brush 69. Accordingly, brushes tti and t!) bridge rings Si and t4 while brushes l' and bridge rings E52 and 53. In the position indicated in Figs. 2 and 5, the segments oi rings E3 and Gt are in radial alignment with respect to each other, but it is to be understood that supporting disc #I and hence ring 54, whose segments are imbedded in said disc, is rotatable in the instant embodiment, through a limited degree o1" movement in a counterclockwise sense, from the position indicated in Figs. 2 and 5, under the control oi knob 22.

Shaft ll, Figs. 2 and fl, of knob 22 extends through escutcheon plate I5, and at its inner endv there is splined a driving pinion l2, which, through an intermediate idler gear i3, Figs. 2 and 3, is capable of imparting counterclockwise movement to an arcuate rack 'i4 integrally associated with the supporting disc tl. The extent to which supporting disc il may be rotated is limited by a stop p 'l5 anchored in the idler gear 3, which is designed to encounter stop lug 'I6 carried by a stationary portion of the frame as idler gear i3 is .rotated both in clockwise and counterclockwise directions.

extent of increment permitted to supporting ,disc and hence to its segmented ring 64, is sufficient so that t' e normal sized segments (start, l, 2, 3, etc., but preferably not the stop egment) may overlap their adjacent segments in ring 63 in a counterclockwise direction to an extent of at least fifty to one hundred per cent. The electrical significance of this adjustment will be considered hereinafter during the explanation of Figs. 6a to 9c. Mechanically, this adjustment produces the aforedescribed overlap oi the stationary segmented ring S3 by the displaceable ring Sli and the precise degree of overlap is calculable by observing the radial alignment of corresponding ends oi any pair of segments in rings ff and 53 with the graduated index or standard Below the 22E there is found a control knob Whose spin le 'li terminates with a crank arm triangularly shaped, as best indicated in Figs.

i and 2, and provided in each oi its corners remote from the pivotal corner with an anchor pin The opposite end louer 3i narrows down to a lug projection of urlicient size to be received within one or the o of a pair of adjacent apertures 8S and 83 or which said lever is shown in engagement with lower-most aperture SE, These apertures s rye as locking means for lever 84, and they are formed at the lower extremity of a latching lever 2S, which is urged by a spring El' in a counterclockwise direction about the pivot member 29.

The upper end of lever 83 is curved so as to be gradiently engaged by a minute cam apex 9i secured upon main distributor shaft 2d. When latching lerer SS is engaged by cam 9i, there results a clockwise rotation of the former against its spring E?, causing to be Withdrawn its lowermost end from engagement with the lug extremityof pivoted lever Sil and depending upon Whether crank arm 'i3 is disposed in the position indicated in i or in its alternative position (about counterclockwise therefrom), lever Sli wiil accordingly be ten cned by spring 82 cour.- terclockwife or clockwise respectively. As a result, upon the release or" iatching lever S8, as aforementioned, lever Sl will be permitted to move from one o1" its positions to the other as iniluenced by sp ing 53 trated, pin 2 carried by lever 84 is withdravh from 'ze insulated extremity of a contact pair Q3, but when said lever 5d is in its clockwise position, n S2 abuts said insulated extremity, effect-- ing the closure of the contact pair for shunting the transmission line with battery The alternative control oi knob 23 causes a tension to be applied to lever 3ft in one direction or another, but the consu. mlation of the control operation is transfer ed to the apex Si of in zn distributor shaft the occurrence of i ch is coincident with the stop impulse of a permutation code signal. Accordingly, no changeover may be cted except during the transit of this signal impulse, which is an inert or non-active impulse so far as a signal selection concerned. This assures the transmission oi complete signals rather than signal fragments such as might other\ se result Where a control .I is directly operated by manual supervision. .nob 2li is secured to and rotatable with a shalt vwhich extends through and is journaled in a pair of side frames 96 and 91, Figs. 2, 3, and 10. To shaft 95 is keyed sleeve 98, the periphery of which is studded with variously distributed iiat spots. Noting particularly Fig. 2, it will be observed that these fiat spots or areas are arranged in three aligned groups angularly separated from each other. Those indicated by the dotted line 99 are at the left of sleeve 98, as viewed in Fig. 2, those indicated |0| at the right of said sleeve, while at |92 is a continuous fiat area shown in this illustration as being engaged by the extremities of a set of bell cranks |93. In Figs. 3 and 4, shaft 95 is shown as having been rotated counterclockwise throughout from Fig. 2, in which case the flat area |92 is disposed to the foreground in Figl 4, or to the right in Fig. 3, displaying in the latter case the particular distribution of the fiat spots 19|.

Bell cranks |93 are similar in contour and the several of them are pivotally supported upon a shaft |94, which is secured at its extremities in the side frames 95 and 9i. Each bell crank lever |93 includes an upstanding arm |95 provided with a cam lug |95 which extends sidewardly and is adapted to engage the periphery of an associated one of the coded discs 3S. Another lug formation lill on each of said upstanding arms |95 is projected in an opposite direction and engages with its extremity an associated flat tension spring |98, as may be seen in Fig. 10. Each tension spring |98 maintains its bell crank in a counterclockwise position with its cam lug |55 urged against the periphery of an associated code disc 3S. With each tension spring |98 is provided two pairs of contact elements |99 and lll the several assemblies including in each case a tension spring |53, and the two aforedescribed pairs of contacts are mounted upon a transverse bail |5I, which is formed with the downwardly extending sides |52 and |53.

The latter side has integrally associated with it a follower arm |59, which rests against the endmost portion of the periphery of sleeve 98. A special at spot |55 in sleeve 98 is adapted to be presented opposite the contacting surface of follower arm |59 when shaft 95 is in the angular position indicated in Fig. 2. During this condition, a tensioning spring H2, one end of which is anchored to the side frame 95, pulls with its other end against an ear |55 also integrally formed with the downwardly extending side |53, and causes the entire assembly, including bail |5| and the several contact assemblies to be rocked about shaft |94, until the cam lugs |95 are engageable by the peripheries of the code discs 38. At other times during the rocking of shaft 95, either clockwise or counterclockwise 90, the periphery of sleeve 98 in the proximity of feeler arm |54 causes transverse bail |5| to be rocked clockwise, Fig. 2, through a limited degree of movement but to a sufficient extent to withdraw the cam lugs |95 so that they are free from engagement by the code discs 38.

It has been noted that the peripheries of the coded discs 38 are preferably cut so as to afford permutatively a succession of signals constituting a test message. As the code discs are rotated in timed relation to shaft 25, through the gear train including elements 33, 35, etc., code signals are impressed by the peripheries of said discs 38 through the bell cranks |53 upon the contact pairs |59 and |ll, but this is possible only during the aforementioned intermediate position when bail |5| and its appurtenances are in their counterclockwise extreme position. The

rotation of shaft 95, 90 in either direction from this position so that the pointer 5l of knob 24 indicates straight R or Y transmission, results in the withdrawal of all contact assemblies from association with the test message code discs 38.

During either of said R or Y conditions of transmission, the fiat spots 99 and 10| are effective to displace certain ones of the bell cranks |93 clockwise about shaft |95 and against the tension of their individual springs |98 effecting the closure of their associated contact pairs |09 and In the particular embodiment, the counterclockwise extreme position of shaft 95 causes to be installed a code combination corresponding to the character R, while the clockwise extreme position of shaft 95 causes to be installed on the contact assemblies the code combination corresponding to the character Y.

The foregoing described mechanism concerning the changeover switch between R, Y, and test message apparatus forms the subject of a separate application filed October 18, 1937, Serial No. 169,625.

At the left of the unit, as viewed in Fig. 1, is found an escutcheon plate vthrough the face of which extend the several toggle switch arms indicated l5, il, i8, i9, and 2| already described. Mechanically, switches l5 to i9 are of a type capable of assuming three positions, two extreme and one intermediate, during the latter of which contact elements under supervision are permitted to assume their normal relationship, but during either of their extreme positions each switch arm eects the closure of one or more sets of contacts. In Fig. 5, contacting elements only of said switches are shown, it being understood that to effect their closure, an associated one of said switch arms need but be thrown to the proper one of said extreme positions. In comparing Fig. 1 or 2 with Fig. 5 it is to be borne in mind that when the foremost portions of any of the toggle levers are shown to the right in Figs. l and 2 then their inner ends are effecting a contact closure toward the left, Fig. 5, and vice versa. The illustrations are in this respect actual and the reader should avoid the suggestive conclusion that the direction of the toggle levers in the mechanical views is the same direction as the contact closure in the disclosure of the electrical connections.

In the use of the terms bias and end distortion, cognizance is given to the uniformity or non-uniformity of signal impulse alterations. That is to say, those changes which affect all impulses equally throughout a signal are referred to as signal bias whereas those alterations which aiect the start impulse in a different manner from that in which other impulses are affected are referred to as distortion. In order to provide regularity in making the observations, a signal has been employed in which impulses are of alternate characteristics successively. Thus, it may be observed that in the examples illustrated in each of the Figs. 6a to 9d, the signal curve starting with the stop impulse has been arbitrarily designated as one of alternate line characteristics, which corresponds incidentally to the character Y. Any other signal might be employed but not with the same utility in affording a wide eld of comparison.

It is toy be noted, for example, in Fig. 6a, that in the distance between the starting point of the start impulse and the termination point of the No. 1 impulse, which distance constitutes a complete signal impulse pattern, there is occupied the same space as is occupied by each succeeding pair of impulses constituting a complete signal pattern. These distances are indicated by the dimensional index A. In the case of Fig. la, which is an example of spacing end distortion, the distance between the starting point of the start impulse and the termination of the No. l impulse is less than that between the starting point of the No. 2 impulse and the termination of the No. 3 impulse. Accordingly, the pattern in the case of spacing end distortion is not uniform, hence the term distortion.

Also, it is to be noted in Fig. 9a that the distance between the starting point of the start impulse and the termination point of the No. l impulse is greater than that between the starting point of the No. 2 impulse and the termination point of the No. 3 impulse. Thus also there is lacking the uniformity which is noted in the two examples of bias signal transmission. Hence here too the condition is described as a distortion because as between one impulse pattern (comprised of a consecutive marking and spacing impulse pair) and another pattern of the signal there is a variation in their lengths.

rEhe importance of this variation is best understood when viewed in terms of a receiving selector which is started into its cycle of operation the instant that the start impulse is received. Thus, in the case of bias signals, the sole effect upon a receiving selector is to delay the instant of starting each signal as a result of which the time displacement aifects equally the receiving selector and the reception of the ensuing selector impulses, but in the case of end distortion signals,

there is introduced in fact an unequal displacement between the period of starting of the receiving selector and the periodicity of succeeding impulses.

The present invention concerns itself in one of its features with providing a novel means for introducing a distortion factor which permits the generation of distortion type signals and of switching instantly and conveniently from the transmission of this class of signals to the class aioredescribed as bias signals. In the illustrations Figs. 6 to 9, there is portrayed fundamentally this novel principle of signal transmission and the circuit arrangements whereby the changeover is eected expeditiously. During the course of the following description, it may be noted that the general principle that is illustrated in Figs. 6 to 9, is also to be found in Fig. 5 but that in the detailed disclosure of Fig. 5, there are contained several additional control devices.

As indicated by the applied legends (bias and end distortion), the upper switching arm I6 is assigned to the closure control of contact pairs IIS and IM the tension of the contact springs themselves sufficing to separate them when the effect of the toggle lever is withdrawn. In this connection, attention is directed also to Figs. 6 to 9 where diagrammatically there is shown in a simplified form the effect of operating certain ones of the switch arms located on the escutcheon plate I4.

In the same manner as aforedescribed, switch arm Il, during its extreme settings (the intermediate one in all cases being neutral) effects the closure of contact pairs H5 and ||6 in one position and contact pair I|`| with contact spring I I8 in its other position. Contact spring HS will be noted as movable between a pair of contact points IIS and I2I. Switch arm H8, during one of its positions, engages a contact spring |22, and during the other of its positions it engages contact spring |23, while switch arm or lever I9 in the same manner is reciprocable between control of contactor springs 24 and |25 each of which is engageable with a pair of associated contacts.

Referring for the moment again to the various rings of the distributor dial I3, Figs. 2 and 5, it will be observed that in displaceable ring 64 the selector segments 26, IZ'l, t28, I29, and |3| each are connected over an individual line VIS to one the contact elements of the aforedescribed set of contact pairs while the other elemen't of each oi pairs it are connected parallelly over a common line :'32, to the junction point |33, thence the one hand over line |34 to one contacter ci contact pair IIB, the other contactor of which communicates over a line |35 with the continuous distributor ring 62 and thereafter over the pair of bridged distributor brushes 5l and 68 which connect the collector ring 62 with the segments of xed ring 63. The selecting segments of ring indicated |36, IS7, |38, IS, and |4I each are connected over an individual path |64 to one contacter of an associated pair III aforedescribed, while the other contactors of each of said pairs lII are connected parallelly over the common circuit |52 which leads to the junction point ids. From here one path is traceable over line IM, contact pair IIS-Hl, line M5 to the continuous collector ring G l while another course is traceable from junction point N3, over line iet, to either oi the contact pairs II4 or I|5. During the closure of contact pair I I4, the course is traceable over the continuation line IQI, which leads to the stop segment 48 in ring 63, and upon the closure of contact pair I I5, the continuation circuit is traceable over path |49, which also connects with line |47 and stop segment |48.

In Figs. to 9, it will be noted that the segmented rings GS and have been indicated conventionally as linear elements rather than as circular elements, but it is to be understood that this variation is employed only for the purpose of simplifying the explanation to follow. The reference character G3 represents the stationary segmented ring, and the reference character 64 the movable segmented ring which, in the simplified illustrations, has been indicated as offset rightwardly to an extent of less than a complete minimum segment overlap. To obtain a condition such as illustrated in 6, toggle switch I6 must be operated to the left in order to close contact pair II@ and toggle switch Il to the left in order to close contact pairs H5 and I I6 (which are simultaneously operated). In order t0 produce a visual image of the generated signal, toggle switch is is operated to the left causing to become engaged contact spring |25 with its contact point |58.

Spacing bias The term bias is also to be construed a signal variation in which signal impulses of a certain current type are lengthened to the detriment of succeeding impulses of the other type where two types such as marking and spacing are employed in signal transmission. A hindermost lengthening of marking impulses is termed a markinfr end distortion, see Fig. 9a, while a spacing end distortion correspondingly aiects the spacing signals as portrayed in Fig. 7a. For classiiication purposes, a differentiation is recognized between front and rear distortion, termed bias and end distortion. In addition to this classification, however, there is also to be recognized one affecting the types of impulses, as .marking and spacing Thus, a bias favoring a marking signal may be specifically classied as a marking bias or, where an end distortion constitutes a hindermost lengthening of marking signals, the condition is referred to as marking end distortion as distinguished from spacing end distortion, which accordingly would refer to a hindermost lengthening of spacing signals. In each instance of bias aifecting one class of signal impulses, it is to be borne in mind, as has tion point |43.

already been noted above, that there results a shortening in the forward portion of ensuing signals ofthe opposite type. The foregoing classification will prevail whether the alternative current conditions be cons-tituted of positive and negative signals or current no-current conditions, etc.

Fig. 6 illustrates a simplied transmitter circuit adjustment which would result in the generation of spacing bias signals.

In Fig. 5, the completed circuit is traceable from signaling line wire 94 as a starting point, thence over branch line |59, contact |6|, and its shiftable contact spring |22 (which is now in its left-hand position because toggle switch i8 is moved rightwardly to the side of the escutcheon plate marked transmit) over line |62 to the junction |63, thence over line |64 to continuous collector ring 62. I-Iere the line circuit is introduced to each of the segments |36 to |4| of xed ring 63 by brushes 61--68 during the rotation of distributor arm 55, parallel lines |64, through an associated Contact pair to the common circuit |42 which leads to the junc- Froin this point, the circuit is traceable over line |44, contact spring H8, and its left-hand contact point ||9 (because toggle switch it at this time directed towards spacing) line |65 to the junction point |66, line |34 `to the junction point |33, which leads to the common circuit |32 connected to one of the contacts of each contact pair |99 as well as to the movable distributor ring stop segment |61. During the closure of certain contact pairs |59, and in all cases as to segment |61, the circuit is extended to the movable segments of ring 64 over branch wires |19 and then by brushes 69-66 to continuous collector ring 6|. Thereafter the path is traceable over line |66 to the junction point |69, spring |23, and its left-hand contact |1| (because the stroboscopic toggle switch I9 is now directed to transmitting), thence out over line |12 to supply battery |13 and ground.

Spacing end distortion Fig. l illustrates a simplified circuit condition under which there may be generated signals having spacing end distortion impulses. This circuit is traceable on Fig. 5 beginning with line wire 94, over branch line |59, contact pair ll-|22 (because at this time the stroboscopic switch is thrown to transmit), lines |62 and |64 to the continuous collector ring 62. Thereafter, the circuit continues over brushes 61 and 68, any one or ones of the several segments of fixed segmented ring 63, and their corresponding code contact pairs over collector circuit |42 to the junction |43, line |44, contact pair ||8| I9 (because the toggle key |1 is directed toward spacing) but because the distortion switch I6 is at this time directed towards end distortion rather than as in the former example to bias, an additional path is traceable from junction point |14, over a line |15, contact pair 1, line |16, contact pair i3, line |11, to the start segment |18 of the displaceable segmented ring 64. Thus, as indicated in Fig. 7a, the principal characteristic of this adjustment is to apply current to the start segment of the displaceable segmented ring 64. Beyond junction point |14 and continuing over line |65, the circuit resemblesA the one aforetraced in connection with the conditions prevailing in Fig. 6.

Marking bias In Fig. 8 there is illustrated the marking bias condition. This circuit is traceable in Fig. 5 as follows: From line 94, over branch |59, through the contact pair |6|| 22 (because the stroboscopic switch is directed toward transmit), over line |62, to the junction point |63, thence von the one hand over line |646 to the continuous ring 62 and on the other hand over line |35, contact pair H6 (because switch |1 is directed towards marking), line |34 to the junction |33, thence to stop segment |61 of the movable segmented ring 64 and also over the collector circuit |32 in the operated ones of the contact pairs |09 and their individual segment lines |19 to the associated ones of the movable segmented ring segments |26 to |3|.

During the operation of the distributor arm 65, the aforedescribed circuits are continued over brushes (i1-68, the' corresponding segments of xed ring 63, and their contact points ||I to the collector circuit |42, thence to the junction |43 and on the one hand over line |46, through the contact pair H4, line |41, to the stop segment |48 of ring 63, and on the other hand over line |44, contact pair ||8|2| (because switch l1 is now directed towards the marking position), line |45, to junction |69, thence on the one hand over line |68, to the collector ring 6| thereby bridging over brushes 66 and 69 With the circuits Whose description Was interrupted at segments |26 to |3|, and on the other hand through Contact pair |23-|1|, line |12, to battery |13. The signals generated in accordance with this arrangement are exemplified by the curve illustrated in Fig. 8a., whose pattern as may be noted, is uniform. Because the increase favors the marking signals (where followed by spacing signals) this classification is termed marking bias.

Marking end distortion In the illustration of Fig. 9, there is exemplied the fundamental circuit for generating marking end distortion signals, which as has been eX- plained are characterized by an elongation of the initial impulse pattern comprising the signal impulses of the start and No. l selecting impulse positions. In Fig. 5, this circuit is traceable from line 94, over branch |59, through the contact pair Nil-|22 (because stroboscopic switch i8 is directed towards transmit), line |62, to the junction point |63, thence on the one hand over line |64 to continuous ring 62 and on the other hand over line |35, through contact pair ||6 (because switch |1 is directed towards marking) to the junction point |66, thence over line |34 to the junction point |33 continuing on the one hand to the stop segment |61 of movable ring 64, and on the other hand over collector circuit |32, operated ones of the contact pairs |09, their individual paths |19 to their corresponding segments |25 to |3I.

Battery is traceable over line |12, through the contact pair HIT-|23 (because stroboscopic 75` dit?A switch is directed to transmit) to the junction point E69. From this point the circuit is traceable on the one hand over line l68 to the collector ring 6i completing the circuits whose description was interrupted above in the segments 25 to ISL while on the other hand the circuit is traceable from junction point over line M5, to the Contact pair iti-H3, line M4 to the junction point idd. From here the circuit is traceable on the one hand over collector circuit 42, through the operated ones oi the contact pairs l il and their individual circuit paths 65 to the associated ones of the segments to lli completing the aioredescribed circuits whose description was interrupted, over he brushes 58-5, but because switch il is ented towards marking and contact pair ii5 is held ajar, the circuit may not continue over une iig, while because contact switch it? is directed to end distortion, Contact pair lll is permitted to come ajar so that the circuit may not continue on to line iii?. As a result, line is withheld from the stop segment M8, indicated in Fig. 9o, elongating the start interval and also the pattern represented by the dimension index L. rihis produces a variation in the pattern as is the characteristic of an end distortion signal.

The toggle switch keys S and i@ jointly supervise the cutting in and out of the stroboscopic iamp al, and, incidentally, the switching between control line @d and a local circuit about to be described.

V/'hen the key head of switch the extreme lett-hand position indicated by the legend linef lished a local circuit eiecting soleiv the strobescopic lamp and communicable t.e two binding posts Edi of This circuit is traceable beginning at the terminal post iti and continuing over line contact point 2da, contact blade E24, line to the inner distributor ring 59, the brushes outer distributor rin t9, line flexible contact blade i255 and its right-hand Contact lino @El to the binding post ZEE. Thus, is to be observed that in this manner switch Si? subjects the stroboscopic lamp entirely to an independent circuit which may be connected to tran: t g vice for producing a visual image upon the stroboscopic lamp it is rotated in synchronism with the transmitting apparatus, and that this image may be compared the standard of measure exempliied by the circular platv which carries the engraving The correctness or the incoming signals ma thereby be ascertained both as to their iengtz, bias, cr other signaing characteristics.

By moving switch it to the right so that its key head is nearest the legend dist however, stroboscopic lamp 4? is connected with a local distribut r apparatus subject, however, to the secondary control which is exercised by the stroboscopic switch This switch must be moved so that its key head is to the left and nearest the legend view in order to establish a circuit whereby a special curent supply indicated by the terminals 2F33 and 29S is introduced the stroboscopic lamp and through the k rig-spacing and bias-end distortion arrangement as already described. The effect of operating switch i3 is to produce a closure of switch blades and 23 with their right-hand contact points Ei! and SM2. The effect of this latter described operation is to introduce local current supply from the source 298-233 in lieu of a line circuit connection and battery 94 and ll'3. In all other respects the marking-spacing and bias-end distortion signaling characteristics remain under the sole supervision of their respective toggle keys i6 and il.

After the bias or end distortion characteristics have been gauged by visual comparison with the circular standard, transrnittinfI operator moves toggle key i3 from the left or view position to right or transmit position. This operation di connects the stroboscopic switch from the .nsmitter circuit and reestablishes the connection, as aicredescribed, with the line Sii, In this 'oer the operator apprised oi the exact sign 1g character'stics which are being issued over the line without regard to any articial or natural inductive or capacitative effects inherent the line.

From the foregoing, it will be evidentthat the present invention contemplates a pei utation uode transmitter having means for variously distor 'ing the impulse components from their normal or l, al proportions in order o provide test signals for determining tbe tolerance of subjective mechanism such as p inters, receiving selectors, etc. in addition, there is also provided a visual index and an annular scale in association therewith. This pparatus a convenient and highly accurate checking medium for observing at once the characteristics or issued test signals.

For the purpose of attenuating and distorting permutation code signals, there is embodied herewith novel means for switching readily from bias to end distortion, which terms have been specifically deined above, and for switching readily from marking to spacing Varieties of either of the aforedescribed signal classications each variation being established independently.

There is also provided herewith a novel mechanism for switching between straight R or Y signal transmission and an integrally associated test message transmitter, the aforedescribed switching eing under the control of a single manual control knob. Another single control knob supervises the performance of an automatically executed changeover switch for cutting in and out the transmitting mechanism in a transmission line. In the execution of the run-stop switch knob, line battery is shunted in ahead of the transmitter apparatus at an instant always coincident with the stop impulse interval.

While the present invention has been explained and described in contemplation of a specific embodiment, it is to be understood that numerous modications and variations may be instituted without departing from the spirit of the present invention. Accordingly, it is to be understood that the present invention is not restricted by any of the speciiic features disclosed in the accompanying drawings nor the ones described in the foregoing specification except as dened by the hereunto appended claims.

What is claimed is:

1. In a telegraph transmitter, a pair of segmented rings, collector rings associated with said segmented rings, a single brush carrier common to all of said collector and segmented rings, means for displacing one of said segmented rings with respect to the other angularly, means for projecting transmission signals through said segmented rings parallelly, and switch controlled apparatus for varying the timing between impulse intervals of each signal.

2. In a telegraph transmitter, a pair of segfil mented rings, the segmentsrof each of which are spaced in accordance with a standard unit isochronous signal, means for displacing one of said segmented rings with respect to the other one angularly for the purpose of overlapping corresponding segments, transmission apparatus for propagating isochronous code signals over the segments of said rings parallelly, and means for distorting the consecutive signal pattern comprising a breaker and circuit connection through oertain ones only of the segments of said rings.

3. In a telegraph transmitter, a pair of segmented rings, means for passing a signaling current through both of said rings parallelly, adjustable mechanism for displacing said rings angularly for the purpose of elongating certain signal impulses by the overlap of their corresponding segments, and means for switching out of circuit certain segments only of one of said rings to prevent the elongation of corresponding impulses.

4. In a telegraph transmitter, a rotary distributor having a plurality of segmented rings, a common brush carrier and brushes secured to said carrier for traversing said plurality of segmented rings concurrently, switching means for connecting the segments of certain ones only of ones of said rings in a circuit with segments of others of said rings, and means for displacing said rings radially with respect to one another.

5. In a distributor, a plurality of segmented rings, means for displacing said rings to effect signal impulse attenuations, circuit connections associated with said rings to effectsignal impulse distortion, a rotatable brush carrier, a stroboscopic lamp associated with said carrier, a rotatable index having markings thereon corresponding to an isochronous signal standard, and means for switching said stroboscopic lamp to associate it alternatively with said segmented rings or with an incoming line so thatv a visual pattern may be produced from incoming or outgoing signals.

6. In a distributor, a pair of segmented rings each segment of which corresponds to an impulse of a unit code signal, a distributor arm and brushes on said arm for traversing said rings simultaneously, means for displacing said rings with respect to each other so as to eect an overlapping of corresponding segments, circuit connections for conditioning electrically certain ones of said segments of each ring in series with corresponding segments of the other ring, circuit connections for conditioning electrically certain ones of said segments in each ring parallelly with corresponding segments of the other ring, and control means for alternatively establishing one or the other or said two circuit connections.

'7. The combination set forth in claim 6 including means ior switching out of circuit certain segments only of one of said rings for thereby eiecting a signal distortion.

8. in a start-stop distributor, a rictionally powered shaft, a plurality oi signal impulse segments certain of which are allocated to permutation code impulses and certain others of which are allocated to synchronizing impulses, means for associating a communication line with each of said segments successively, and means for connecting and disconnecting said associating means with a line comprising a manual spring tensioning member, a switch controllingY member urged into alternative positions by said tensioning member, and a dual position latching pawl for said switch controlling member under the supervision of said shaft and operated by said shaft at a definite period only in its rotation.

9. In a start-stop distributor, a rotatable shaft, a stroboscope lamp carried by said shaft, a set of transmitting segment rings, a set of stroboscope lamp rings, means for associating said transmitting rings with said lamp, means for associating an incoming line with said lamp, said two associating means being operative alternatively, and an annular index having markings in accordance with a signal standard thereon to compare with the visual pattern produced by said lamp for either incoming or outgoing signals of said line of said distributor.

10. In a transmitting distributor, a nxed segment ring, a displaceable segment ring, the number and relative proportion or the segments oi one of said rings being the same as that of the other, means for rotating said displaceable ring to cause its segments to overlap their corresponding ones in said fixed ring, and reversible circuit connections for conveying signals through corresponding segments of said rings serially or parallelly.

ll. The combination set forth in claim 10 including means for cutting out of circuit certain segments only of one of said rings to produce a special variation in a particular signal cornponent.

12. In a transmitting distributor, a nxed segmented ring, a displaceable segmented ring, the number and relative proportion or" segments of one of said rings being the same as that of the other, means for rotating said displaceabie ring to cause its segments to overlap their corresponding ones in said fixed ring, and circuit connections i'or projecting signals through corresponding segments of said iixed and displaceable rings serially.

13. A distributor having a nxed segment ring, a displaceable segment ring, the number and relative proportion of the segments of one of said rings being the same as that or' the other,

means for rotating said displaceable ring to cause its segments to overlap their corresponding ones in said lixed ring, and circuit `connections for projecting signals through corresponding segments of said Iixed and displaceable rings parallelly.

la. In a telegraph selecting system, instrumentalities for determining the degree of tolerance to signal distortion to which a receiving apparatus is capable of responding correctly comprising a pair of segmented rings, the segments of which are similarly spaced each to each in accordance with a standard unit isochronous signal, means for displacing one of said rings with respect to the other one angularly for thereby producing an overlap of corresponding segments, means for projecting code signals over said corresponding segmented rings parallelly, and means for distorting a single impulse in a signal comprising a circuit breaker associated with a corresponding impulse segment and manual means for operating said breaker.

15. A distributor for issuing bias signal impulses comprising a plurality of segmented rings certain of which are displaceable with respect to others to effect an overlap of corresponding segments, a brush carrier for bridging all of said rings with associated collector rings, a manually conditionable switch, and a control cam associated with said brush carrier for operating said switch at a denite angular position with re- 75,.

spect to said plurality of segmented rings after connections for controlling the characteristic of it has been conditioned manually. bias, and manually controllable switch means for 16. A machine for issuing bias and end distoreffecting end distortion by cutting out of circuit tion signals comprising a rotary distributor havcertain ones only of the segments of said rings. 5 ing a pair of similarly segmented rings, means for 5 displacing said rings angularly from each other EDWIN W. F. I-IANKE. to eiect signal attenuation by overlap, circuit WALTER J. ZENNER. 

